Can you have chemistry with someone but have bad sex?

I was talking to a friend of mine who is currently dating another girl. He always talks to me about how he doesn’t ever want sex as much and how he feels like sex is bad with his girlfriend. He said that they have a lot of chemistry but that it was nonexistent when they had sex. I’ve heard this before and it really made me think so if you really feel this way about a person do you really have chemistry with them?