When it comes down to it, Pygmalion's got a lot more violence than romance. Higgins and Eliza come closer to killing each other than loving each other, and pretty much everyone's single. Mrs. Eynsford Hill and Mrs. Higgins must have been married at some point, but we don't hear anything about their spouses. Pickering and Higgins are confirmed bachelors.
Sure, Freddy's crushing pretty hard on Eliza, but we get the feeling he's a bit, shall we say, immature; and Eliza doesn't seem all that interested in him. Except when she's trying to annoy Higgins. Still, she's so modest she won't even look in the mirror. In the end, Alfred Doolittle's pretty much the only one who even comes close to getting any lovin'. He certainly seems to like getting married, anyway.