Venus is a Roman goddess of love and beauty. Loki is "a major diety in the Norse pantheon" [Wikipedia]. So how did the two of them meet? Well, easy, when they're both comic book characters. Chances are most comic book readers of the time didn't know the difference, and if they did, probably didn't care.
"Venus, goddess of love that you are..." Buy your wife or girlfriend a Venus costume online!
Venus is a 1940s-'50s character most often associated with Bill Everett, who did some terrific stories featuring the beautiful goddess. This pre-dates the Everett era, though. Venus #6 is from 1949. According to the Atlas Tales website, several artists worked on this 3-part story, including Pete Tumlinson, Pierce Rice, Chu Hing, and other people from the Marvel bullpen who chipped in.