Seal Says Heidi Klum Cheated On Him With "The Help"

Seal decided to drop a BOMB on photographers when he landed at LAX last night ... he surprised them by telling them EXACTLY what he thinks about "rumors" his estranged wife Heidi Klum has been hooking up with her bodyguard.

In a completely unexpected move, a guy who is normally silent and sometimes combative with the paparazzi, Seal decided to unload and vent to photographers, giving them the "answer that you've been looking for for the past seven months" and here it is ...

A paparazzi videographer is shopping a tape that X17 has viewed, in which Seal tells the paps the following:

"Look boys, that's what happens when two people separate. They move on and that generally means [they have] other people in their lives. I necessarily don't expect to Heidi to all of a sudden become a nun, but as always, my main priority is the emotional well being of our children."

We started slowly so now for the payoff ... here's Seal's JUICIEST statement:

"To be quite honest, if there is going to be somebody else in their lives, I'd much rather it was a familiar face. I guess the only thing I would have preferred is that ... I guess I didn't expect any better from him, I would have preferred Heidi show a little bit more class and at least wait until we separated first before deciding to fornicate with the help, as it were. But I guess you now all have the answer that you've been looking for for the past seven months."

Klum filed for divorce in April. The couple have three kids together - Henry, 6, Johan 5, and Lou, 2 -- and Heidi has daughter Leni, 8, from a previous relationship.

During a recent trip to Sardinia, Italy, Klum was photographed in intimate situations with her bodyguard and X17 has video of Heidi, the kids, and her bodyguard, returning from that trip back to LA on the 28th. Klum went out to dinner at BOA the following evening, without her hunky bodyguard ...