NC for this as DH sometimes reads MN threads and I don't want this tied to other posts.
I've suspected DH of an affair of some sort, I don't think it's anyone in real life if I'm honest but suspect someone he'd have talked to online. He's been going to bed later than me for some months now and will come to bed at around 2am, sometimes as late as 4/5am at weekends. He's not going out anywhere in that time as I'd be able to tell, think gravel driveway and security flood lights would come on to alert me (I'm a light sleeper).
I've had it out with him in the past that when we spend time together when our children are sleeping, he gets tired and alludes to needing sleep after about an hour. I then head up to bed expecting him to join (as he's so tired) and he stays downstairs for several hours. His excuse is that he was tidying this or that, or logged on to his work laptop and it's woken him up so he's stayed up reading/watching TV/doing a crossword. I can't prove anything, I've tried sneaking downstairs but our staircase is so creaky he knows when someone is coming.
So I've tried to put it to the back of my head, until today. I noticed him typing a message on his phone, he then did a swiping action as if to get rid of whatever application he was using or potentially get rid of a message. I felt this was strange in itself considering he is notoriously bad at responding to all and any messages and will always leave all applications on his phone open to the point it's quite sluggish. That wasn't what did it for me though, it was that I watched him and as he put his phone down, he caught my eye and I smiled at him. What followed was him with a look of worry with a fearful frown for the next 5 minutes after as if he'd been caught.
There's a few other things that involve ILS seeming a bit more secretive around me lately and DH not telling me what's going on with family much anymore but I don't know whether I'm just being paranoid. I feel that his going to bed so late with those excuses are red flags alone but the look on his face today has made me feel more justified.
I'm not sure where to go with this but feel like I need to know for sure. What am I looking out for now?