Did Spencer cheat on Heidi?

Oh the horror! Now she'll probably cope by having 12 more plastic surgery operations......
Exposay:
Heidi Montag and Spencer Pratt creates drama for The Hills. In the sneak preview of the upcoming season of the MTV reality show, the couple gave the audience a glimpse on the tension the two have.
Montag says on the clip: "When we get back to L.A., I need you to move out. I gave up everything for you! I'm not the one who wanted to see other people!"
In the latest issue of Us Weekly, the two have opened up what is happening to their relationship.
The 21-year-old aspiring singer says, "Spencer and I have really had our ups and downs this past year. I've definitely been betrayed by friends before, but I've never had a boyfriend do this to me."
"Spencer and I may differ on what it means to cheat."
Meanwhile, Pratt gives a less revealing statement on what happened saying, "We're definitely on a roller coaster. I'm not too happy about a lot of things."