First off - DH was cheated on 'cuckolded' by his Ex-Wife, and we both always swore blind we would end the relationship with each other if we fell for anyone else.
I trust him to stick to that, or i thought i did.
This woman is a very long term close/best friend for both of us - 20yrs+ and the friendship does have its risque banter between all of us.
They did sleep with each other once before DH & I became a couple.
They did fall out for a couple of years because of his inappropriate behaviour towards here and his reactions around her meeting men - he reacts, TBH, like a jealous boyfriend and gets almost stalkerish, looking them up on FB, telling her off for taking risks with them...etc.
They spend a lot of time together and it has been joked that other people would think they were having an affair... the 3 of us have talked about it and joked about it, but i trust both of them, mostly because of the first point i made.
However.
A couple of times i've found messages of his and evidence that he's bought her, or offered to buy her underwear, most recently a negligee.. his story (i asked why he was buying it for her) was that he was showing it her to ask her opinion on getting one for me, and she asked him to get one for her as she didnt have an ebay acc.. and he did, and had it mailed directly to her.
Now.. imho, that makes it look even more dodgy, because i knew nothing about it.. surely a 'BFF asked me to get her one when i bought this for you because she liked it' conversation would have assured the innocence of it?
This is on top of another recent 'jealous bf' reaction to her gaining another new boyfriend.. he stalked the bloke on FB in the name of 'protecting her, i want to know who he is'
I dunno.. i just, i've always trusted them, and he seemed quite defensive when i asked about the negligee purchase, and has since refused to get something she has for him (she makes jewellery and he commissioned a bracelet) because i might think its a bit of a co-incidence.
So now i'm sitting here feeling faintly guilty and running my head in circles wondering if he's just not being aware of boundaries, or if they're taking the piss out of me.