I think in the present, Spamton is more obsessed than Tenna.
Think about it, while Tenna more openly harbours resentment towards Spamton, it's more along the lines of "I wish we never met in the first place". While the breakup did badly affect him, it's only one part of a bunch of other incidents that caused his life to spiral. He's also hung up the Holidays and Dreemurrs no longer watching him
Meanwhile Spammy FUCKING HATES Tenna, that one phone call ruined his entire life and it was all because of Tenna's greed! He harbors hatred for a lot of Darkners, but ESPECIALLY Tenna as evident by the sweepstakes. You know what they say about love and hate being 2 sides of the same coin? Even though Spamton knew of Tenna's death, he still wanted to kill him with his own hands. If he didn't originally love Tenna so much, he would've just been happy about that part of the prophecy and moved on.
Bro was imagining Tenna's [Cathode Screams] what a fucking faggot.