Back to the original question, no you should not fake it is a form of lying to them as was said earlier by somone (I forget who I am sorry) dosnt give them the opportunity to change things so that you enjoy it. There is a chance at anytime that they can find out that you was faking it and it could be the end of the relationship.

I really would get this sorted out BEFORE I tried for a baby.

After having a child you could find the feeling of not wanting to make love even more intense as babys can really tire you out.

Also sorry to be a pain in the backside but could this be moved to the sex forum ?