[FirstYorkie]

Male dogs don't go into heat.

And, yes, left unchecked this marking behavior is likely to continue. Most (but, unfortunately, not all) males stop marking once they have been neutered. If you get them neutered as quickly as possible when they start this behavior, the odds of this stopping the problem are improved.

Otherwise, you have to treat it like a housebreaking problem. Watch him constantly. Immediately interrupt pottying in the wrong place and rush him to the appropriate spot. Heavily reward (with praise and treats) pottying appropriately. Contain him when you can't watch him.

Good luck.