It is possible he could be sorry? I know I do not have any info I just think that if you have to sit next to him perhaps it's best to try and find out why he did this now? Sometimes misunderstandings are at the root of bad feelings. I have had to sit next to a nasty co-worker and it was hell. I found that just smiling and saying hope you have a good day disarms them. And they don't see that they have gotten to you, that it's not a big deal. Good luck.