Things to do on a layover at Munich Airport

I have a friend who has arranged a 4 hour layover at MUC just to have a chance to see me. The time seems too short to take him anywhere. My place is an hour away. Any ideas? The time is in the morning to early afternoon.

drinking at the AirBräu? My brother is coming in March, and that is our first stop.

Hotel Kempinski Spa as a day guest.

Both good ideas. Thanks. The spa would be very interesting if he were a she, but according to the website, the sauna and steam rooms are not mixed-gender, so we couldn't do that together. We could just go swimming though. So that's an idea...
Edit: wait, now I see there is a mixed sauna as well. Apparently, there's only segregation in the steam bath. This idea is looking more and more interesting. Where to get him a bathing suit though...
Edit 2: I just remembered, I do have some men's swimming trunks!

What does he need a bathing suit for?

For the pool.

Silly you, Fallen Angel.

Ah. Missed the part about the pool. I thought we were just talking about the sauna.

Freising is only a 15-minute bus ride away, with plenty of cafe/restaurant/sightseeing options. Bus 635 departs every 20 minutes.

Erding Therma is only 15 mins away. one of the biggest Thermal baths in Europe. 14 Euros for 2 hours.