I am a devout Catholic, and have been married for 1 year. My husband has been wanting me to do things in bed.?

He wants me to ********. I am not comfortable doing this but have done it anway because I wanted to please him. Although I think this is against my beliefs. I am a devout Catholic and don't know if this is against my religion. I am kinda innocent when it comes to these things. My question now is, what should I do? is a sacred thing that a married couple share, so I am not sure if this is right.