So I've been seeing my S/O for about 4 months now. We've never had issues in the bed. But the last 2 weeks he hasn't wanted to have sex at all... even on my birthday we didn't it was the next day. But should I be getting worried?! He says his stomach hurts or just not in the mood. He laughs about it sometimes too and I just don't know what's up. I've tried asking him.