Was this your first business trip away from Mojo or is this something you need to do on a frequent basis?
If the answer is the first...that is most likely the reason he poopied and teeteed on your furniture. Even if it was 2.5 months ago that you took your trip...to him it's recent. Contrary to popular "opinion"....dogs hold grudges just like people tend to do. "Mommy left meeee....take THIS mommy!!" (in a manner of speaking). Dogs are brilliant, but they don't have the capacity to reason in entirety like humans can. He doesn't know you went on a business trip and were not able to take him with you. All he knows is that you walked out the door without him and didn't come back for a week...so he's Teed off, and he's making sure you know it. lol!
If it's the latter of the two...perhaps the first reason would still be applicable. He probably just missed you a great deal, and was perturbed that you didn't take him with you (I know it couldn't be helped, things happen).
Maybe it would help next time, if you brought back a TON of goodies with you just for Mojo. Bully Sticks...toys...squeakers...treats...chews, etc. At least then he would associate your return with something VERY positive instead of focusing on seeking revenge by pottying on your couch(es).
Dogs are funny little critters
