The fit is not as important as it is for diaphragms.
Getting back to the original question, some partners don't like it, some positively do like it, and most don't care. You need to talk to him to find out which he is.
But if you're not comfortable with the idea, you need to postpone the date: losing virginities can be stressful enough without any extra worries. Whenever you go for it, agree that either can say 'enough for now' without any problems from the other.