Should I still give him oral sex if he may be divorcing me once our son is born?

Christina
In April, my husband of 11 years, when I was 6 months pregnant, told me he was unhappy and was considering a divorce. Two wks later I found he'd been texting someone 150 texts a day for over a month. When I asked who it was he said it was none of my business. Claimed she was just a friend and that he would stop talking to her. I'm currently 35 wks pregnant, we still live together and split bills (we have a 9 yr old daughter). He shows no affection for me but still wants me to give him oral sex when he wants it cause "he has needs" (doesn't want sex because I'm fat and he's not attracted to me and hasn't been in years). I have been doing this but I feel like I'm being used. I originally agreed to it so he wouldn't physically have an affair but I'm beginning to feel like he's just living it up and will delay any decision making cause he has it made at home. I'm hurt but still don't want a divorce. Should I continue taking care of him sexually to possibly save our marriage or tell him no more until he decides whether or not he's staying and willing to save our marriage?