I'm looking for a manga.. all i can remember is that
the main guy (i think he was the president of the company they both worked for) hired the second to pretend to be his lover to keep his mother off his back about marriage. (the second guy accept cause he needed the money for an air-conditioner... or something like that) they moved into the family house and lived like a happy couple to convince the mom who just wasn't buying it.

This is my last resort I've looked everywhere, but can't find it. I don't remember the mangaka, the names of either one of the characters, or what letter the titles starts with.

It's probably Hanayome Sengen by Tamaquis Wren.