1 definition by DrMoon

When one man is getting it on - sexual or romantic contact of some kind - with a woman and his twin brother, similar-looking sibling, or other well-known look-alike joins in the encounter, unannounced, and unacknowledged by either party.

(like Dr. Manhattan clones himself and performs sexually with Laurie in "Watchmen")

This can also apply, though less often, when two twin females perform the same act. The common term for this is "AWESOME."
Brad was totally hooking up with Lisa, when his brother Jeff walked in and they gave her the Dr. Manhattan!

Also as a verb:

Jim and Bill completely Dr. Manhattaned Jim's girlfriend last weekend, and she LOVED it!
by DrMoon March 2, 2010
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