My BF has a 4 year old son and we’ve been together since the son was two.  He is a great kid and has become my little BFF.  He’ll ask me to play with him, make him dinner, and just cuddle sometimes.  We got a few sets of matching PJs and he picks them out when he wants us to wear them.  Problem is BM hates me and my BF is quick to remind me (in subtle ways) that I’m not a parent although sometimes he wants me to have the responsibility of a parent like spending all my Saturdays doing kid stuff.  I don’t mind playing the role and genuinely like spending time with him but and I being a sucker for revolving my time around this kid and getting so attached when a breakup could mean I’ll never see him again?  BTW, we live together and have him half the week.