I need some advice...

So my fiance and I usually have sex at least 3 times a week give or take. But this week we haven't had it at all. And, not only this week, he always gets upset and tells me that I don't think he's enough whenever I try to initiate things when its unplanned. Now we do live with his parents that don't know we are doing anything so that's part of it.  But we've done it lots of times and his parents never found out. Should I be worried? He always makes me feel guilty for asking and me asking makes him feel like he's not enough for me.... Am I out of bounds thinking he's trying to manipulate me or something? I'm really worried. If someone could help that'd be great...