Dean McDermott Claps Back at Trolls After Tori Spelling Supports Relationship

Dean McDermott's firing off at trolls shocked at Tori Spelling's acceptance of his new girlfriend ... this despite seemingly obvious tension between the exes.

The actor jumped into the replies of a post featuring his new girlfriend, Lily Calo, to defend himself and his estranged wife after several fans said they couldn't believe Tori liked the post ... essentially showing her support.

In response to one comment which seemed to really upset him, Dean wrote, "It’s because she is a highly evolved and compassionate loving person, which is a lot more [than] I can say for the trolls commenting on this post."

A serious burn on the commenter ... followed by McDermott's view some people just work better together when they're not married -- and, adding TS has her own boyfriend too, so they're both moving on.

It's a pretty fiery roast from the father-of-five ... and, it lifts the lid on a relationship that's been hella strained recently.

Remember ... the two announced the end of their marriage last summer -- and Tori and their kids were bouncing between motel rooms and family friends' homes because she didn't seem to want to be near Dean.

BTW ... Tori's dropped other sweet comments too like one where she says she loves Dean and Lily. Talk about a 180!

Of course, Tori filed for divorce from Dean officially at the end of last month ... and, broke the news to him live on her podcast days later. There seemed like a lot of tension between the two at the time -- but, now it sounds like they've moved on.