Looking for a 4th

Three guys go to the golf club looking for a 4th, as their buddy moved out of state. They find a guy sitting at the bar.
“Yeah, I can play a round with you guys on Saturdays, but there might be times when I’m a little late.”
They head out to the course, and the new guy is amazing. Clearly a better player than the other guys. They have a good round, then make plans to meet next Saturday, same time. “Dont forget, I might be a little late,” the newcomer reminds them.
The next Saturday, the guy is on time, carrying left-handed clubs. Another amazing game, he easily out-plays the others. They finish back at the club, plan to meet again next week. “Don’t forget, I might be late.”
The following Saturday he is on time, with right-handed clubs again, and has yet another amazing game. As they head back to the club after the game, one of the guys asks, “it’s amazing how good you play, both left and right-handed. How do you decide which way you’re playing?”
“Well, when I wake up in the morning, I see how my wife is sleeping. If she is laying on her left side, I play left-handed. If she’s laying on her right, I play right-handed.”
“What if she’s sleeping on her stomach?”
“Those are the days that I’ll be late!”