long long ass story bewared but I'll try to cut down without leaving to much important info out.
DM met L 10 years ago, L is still married and has a child with another woman. When she did everyone and everything was dropped for him. She'd make plans and not bother to show up. She'd cancel last minute with a crap half assed excuse which wasn't true and it'd turn out she'd be with L etc. L is the type of person has an opinion on everything, He has to share said opinion on everything with everyone and will argue the toss with you about how you're wrong and he's right. (He actually argued with DSis about where she was at work, how she was wrong and how he knew she wasn't in Y but was in X because he went there when he was younger. Not only was he in another country, he was of course wrong.)
After months of him telling me how I was raising my child wrong, he has a DD and knows better, what I should and shouldn't do with him and her constantly flaking on DS1/me and even buggering off during DSis wedding repeatedly as she "needed to spend time with L" on their day to the point the guest assumed the MOB didn't attend! I didn't speak to DM for 4 years. The wife also found out about the affair but that didn't stop them.
We reconciled and despite her still acting like a teenager with their first boyfriend I thankfully never had the misfortune of being around him until recently. They worked/lived abroad to avoid L's wife for years and he'd occasionally come home to see them. Any visits/holidays/trips etc had to be planned around L's return home as god forbid she'd go out and leave him by himself.
Last year they returned to work/live in the UK, L went back to the wife and his daughter, barely had contact with DM and DM fell into a routine of coming to see my DC midweek and once on the weekend, she was always wanting us to do things, go shopping etc which we usually would.
This brings us till last month. L and DM went away whilst L's wife and DD went away to which she found out. She turned up at DMs house had the affair confirmed again and subsequently kicked L out. L will tell you he wasn't kicked out but he chose to leave after she threw his stuff out the window. DM had plans with Dsis and us to which she bailed on with no contact, days later she pitched up and gave a grand old speech about how she's told L "I've made a life since you've been back with your wife, I have plans and routines with DD's and the GC that won't change". We obviously suspected this was BS and wouldn't last and this is where we are now.
She went weeks without seeing my DC without a word because "I can't leave L in the hotel by himself." When she finally saw DC it was cut short because L had finished work and she was going to back to see him. She asked if he could come to my DS birthday at the beach to which we reluctantly agreed and it was a shit show from the get go. She arrived late, she swanned off for 1.5 hours under the guise of "getting a tea" from the cafe 10 steps away with L and L spent the whole day telling me what to do with my DC. "Why isn't DS wearing a t-shirt", "you should put this sunscreen on DC not the one you have", "pull DC socks up so he looks cool", "DC sit down", "DC come do this" "why isn't DC eating this instead of that" etc This lasted all day, over every decision I made as a parent and through DS birthday meal. I repeatedly told him to stop to which he ignored until I loudly stated that "I didn't remember sleeping with him as far as I was aware he's not their father and I didn't ask for parenting advice" he proceeded to sulk the rest of the meal and DM said nothing.
As part of DS birthday Dsis had agreed with DM back in March to take DC away due to me working the weekend. Due to it also being DM birthday weekend we agreed to go out for dinner. Now L was around DM spent the past two weeks trying to chop and change plans and trying to add him onto things without asking if it was ok or if there was room. Due to this the travel plans were changed First, DM was meant to go with DSis, BIL & DC then she changed it to they'd meet her at her's and they'd follow each other. On the day, an hour before they're meant to meet she decided she'd make her own way with L and they'd meet them there. Because L knows best and didn't need directions or to follow them they ended up 40 miles away in the wrong direction at a different holiday park. When they finally got to everyone else it was the afternoon, they then left halfway through the afternoon to attend a viewing on a flat they decided to book for that day and returned 2 hours later. L had also decided he had to be there for dinner and wanted to go to a restaurant where minimum spend for a private plastic 'pod' was £250 and they only served roast dinner on a Sunday. Something nobody wants at 27 degrees and DC wouldn't eat.
True to fashion when they were there L knew everything about everything and was apparently a PITA, was carrying on with his telling DC what to do and not to do etc. When I spoke with DM later that day I asked her the plans for the following day (she was meant to take DC home and we'd have a meal) I told her I didn't want L driving DC as I've seen him drive before and he's an angry, showboating idiot on the road and she agreed she would drive. As far as I knew everything else that day went ok DC all crashed early and were content.
That was until I got a phone call the next morning when they were on their way home. DM and L had buggered off home that night when she was meant to stay. They promised they'd be back before DC were awake around 7 and it was now 9 with them still not there and hangry DC. When they finally arrived at gone 11 L argued with everyone about what they wanted for breakfast (BIL said he wanted beans on toast and L told him he didn't he wanted a fry up, Dsis would want Y and he's argue how she wanted X etc). The original plan was Dsis and BIL were leaving at 9 to return home and DM was staying to do activities with them, she then asked them to drive DC home because L wanted to drive.
It was at this point I lost my cool. I rang DM who made a whole song and dance about connecting me to the car handsfree to act like she was driving and asked her why Dsis and BIL were driving DC home. She admitted she told Dsis to drive them as L wanted to drive and seeing as I didn't want him driving my DC that was the only option. I told her I didn't think it wasn't fair that she'd made all these promises to DC, DSis, BIL etc and she continued to flake. L then proceeded to lose his shit. "who the fuck do you think you're talking to?!", "why the fuck can't I drive your kids?!", "you need to fucking understand im with your mother you're not important I am", "you and Dsis are fucking shit stirrers", "you're a cunt", "you're a fucking bitch" etc. I'd tell him I wasn't speaking to him I was trying to talk to my mother and he'd go on again. I told him him point blank I didn't need to talk to him and he if he wanted to parent someone to parent his own child to which again I was called a "nasty cunt" and told "get someone else to look after your fucking kids, she's not fucking looking after them anymore, you're a fucking bitch" DM sat there and let him carry on saying "I'm not getting involved".
I told DSis what happened and to bring the DC to me and don't leave them with them. Apparently DM said nothing to Dsis and BIL chucked their stuff at them and got back in their car and shut the door. No goodbye to DC etc. Dsis and BIL were rightly fuming and I left work early and came to meet them. Later that day I contacted DM to say DC still wanted to give her her presents but I had no desire to see L and L was to be know where near DC. L started screaming I was a "selfish stuck up bitch" and demanding to know why I wouldn't let him see my DC. He can go "anywhere he wants and I'll see your DC if I want". DM told me that L was "the most important person in her life" and "we all have to accept that they're together and they come first" this was followed by I "didn't get it L is having to find a house all by himself and she's the only person who understands that". Completely ignoring the fact I moved out lived alone with DC1 at 18 and have lived alone/moved alone since!
"if you won't let L see DC then I don't know when I'll see DC as we will always be together so that's your choice but I will not be forced to pick sides". Nobody wants her to "pick sides" except L who has repeatedly said "we're all jealous he's number 1 in her life now and he will always be first" The irony that he's still married to his wife and is only around as she kicked him out isn't lost on me however.
She still wants to see DC apparently, she can't say when, for how long or a day etc and it'll depend on if she's with L but she'll tell me on the day she's free. DC do like her and enjoy spending time with her but rely heavily on reliability and routine. My eldest DC has said he doesn't want to see or speak to L again after hearing the way he spoke to me and at the moment he doesn't want to see DM at all, I ofc won't make him. However, if i'm being honest I think i'm done. DM knows I have 0 problem with cutting people off (DB was a nasty abusive piece of work and I went NC 9 years ago without looking back) She's already had 1 chance and despite it being quite some time I know we're back to square one. OFC I don't expect to be the forefront of her life, but I certainly don't expect DC and I to be thrown away and used when she's nothing better to do.