Lots of evangelical Christians say exactly this. If you believe homosexuality is a sinful choice with no genetic component, the better choice would have to be to stop being gay. Any resurfacing of homosexual leanings, which would in fact be due to the genetic component, would be interpreted, rather, as the stirrings of a sinful choice which you'd have to keep avoiding by choice.

So in effect, the person is recommended to stay in the closet. The conservative Christian wouldn't say this is a matter of "pretending," but of choosing to be your best self.

The bigot even has scriptural backup, since he or she can appeal to Matt.5:30: "And if your right hand causes you to sin, cut it off and throw it away; it is better that you lose one of your members than that your whole body go into hell."