One of the trademarks of Harold Pinter's plays is that some note of menace inevitably enters into the scene. It can be prolonged and painful, as when the two enforcers visit Stanley in The Birthday Party, or it can be relatively quick as in the two short plays I saw at the Shakespeare Theatre Company Sunday: The Lover and The Collection.
The latter turned out to be the interesting play. There's a pitting of two men with one menacing the other, whom he believes has been having it off with his wife. That such an event might have occurred is problematic because the man accused appears to be living with a third man with whom he seems to be engaged in a gay relationship.
In the first play, the shocker comes at the start when a husband asks his wife if she is planning to entertain her lover that afternoon. By the end you don't know whether they have an "arrangement" or whether this is merely a role play for the two of them, although there is indeed a scene in the afternoon with her lover present.
In The Collection, you are left adrift as is usual with Pinter but the perplexity comes from a gradual perception that the accused man may be playing a game on both the man with whom he lives and the man who is accusing him of adultery. The performers are superb: Lisa Dwan plays the woman in both plays--we saw her in June doing a one-woman show, No's Knife, based on some Beckett pieces, at the Abbey Theatre, Dublin. Patrick Ball, Patrick Kennedy, and Jack Koenig are all excellent, and also have international appearances on their CVs.