BT1 / WENN 1 / 4

By Kat Giantis

Ryan Phillippe and Amanda Seyfried did some damage control on Wednesday amid rumors that he's knocked up his onetime girlfriend Alexis Knapp.

Paparazzi just happened to be on hand as the fair-haired, camera-ready pair went for a jog in the Hollywood Hills.

The outing made it clear that their somewhat fickle four-month romance is still a go, despite the possibility that he may soon become a father for the third time thanks to model-actress Knapp, who is reportedly due in June (Ryan is already dad to 11-year-old Ava and 7-year-old Deacon with altar-headed ex-wife Reese Witherspoon).

"Ryan and Amanda looked totally in love," enthused a shutterbug of their exercise session.

Meanwhile, no love appears to be lost between Phillippe and Knapp, who dated (apparently casually, according to sources) last year.

TMZ says the actor is ticked off with talk that he's been tightfisted with his former flame.

RELATED: Amanda defends Ryan over Rihanna rumors

Her camp claims he hasn't contributed to the care and feeding of the work-limiting bun in her oven; his camp insists he's generously paid her expenses, even though he wouldn't have to until paternity is established.

Adding to Phillippe's alleged anger: Knapp supposedly agreed to keep her piehole closed in exchange for his financial support (according to Us Weekly, she spilled the beans last month at a party, and he was "blindsided" after hearing it through the grapevine. People, however, says he knew about the pregnancy from the beginning).

Harrumphs a Ryan insider, "File this under the category 'No good deed goes unpunished.'"

Knapp's rep is taking aim at the accusations by denying that the starlet has accepted Phillippe's cash -- or blabbed about the baby.

"She has never asked Ryan for any help, nor does she expect it," her rep tells People. "Alexis has maintained her silence and will continue to do so. Any 'source' claiming to have been her or her camp up to this point is false."

A Phillippe source has assured Us that if the child turns out to be his, "He'll take responsibility."

Read more Hot Gossip