I realise I'm probably going to get some stick for this but I'd like to see what other think 
I'm not overly concerned but do find it a bit strange.
DP has always said he finds it disrespectful liking opposite gender pictures etc on social media so has never done it (I don't agree but since he finds it disrespectful, have never done it either).
It got brought up in conversation a while ago, and he said he doesn't really care anymore.
I've since come to find (I haven't purposely gone out of my way to find this) that he has been liking a fair amount of this one woman's Facebook posts and pictures. No one else's. He also follows this woman and only this woman on Instagram. He doesn't even follow his family or friends on Instagram and has actually once before asked me to unfollow people on Instagram.
He knows this woman from a few years ago, apparently one of his friends ex's but has never been friends with her or spoken to her much.
Like I said, I'm not overly concerned, not even concerned at all really. But I do find it a bit odd and I am curious as to what he would say if I asked him, but I'm probably not going to.
Probably find it more odd since its not his usual behaviour and it's only come around since our DC arrived and our sex life has been a bit non existent 
and he has "jokingly" made comments about understanding why men cheat when the topic of me not wanting to sleep with him has come up.
In all honestly I don't think he would cheat but I think he would show interest in another woman without actually acting on it if that makes sense.
Curious to see what others think!