Casper Smart and Jennifer Lopez are talking again and on friendly terms … the only difference is J Lo broke up with him and he’s in denial.

Casper flew to NYC to be with Lopez, who’s there for 4 months shooting her TV show, “Shades of Blue.” Sources close to both of them tell TMZ, their relationship is “amicable” and they are still great friends with a lot of affection and history … but J Lo has made it clear … they are no longer a couple.

As for Casper, we’re told he is not accepting the breakup and is in strong denial. As we reported, the last straw in the relationship was Saturday night, when Casper blew off a big fundraising event in the Hamptons — an event where J Lo wanted Casper to accompany her — to attend UFC 202.

Casper thinks it’s just another fight, but J Lo is resolute — the relationship is over.