Just to be clear: I didn't do it the first time.
I was ROFL at a different part of the sketch, because at our house we do in fact have a bucket full of toys next to the bed, and I can just imagine me OR my wife going "You mean I have to choose? Okay, I choose this one for Monday, that one for Tuesday, both of those for Wednesday, and Thursday ... are we inviting company over Thursday? Oh, good. We'll need several then." The bucket presented in the context of picking just one is ridiculous and makes good comedy because the character even though deliberately trying to coarse, is herself such a prude as to not embrace the power of AND.
I see May's use of vulgarity as serving the purpose of comic relief, so even if it was in character, the specific line about the bookmarks was a fail. Even if the character is deliberately offensive, it fails as comic relief if more than half the audience is too busy being offended to laugh. If, as in this case, there's a good May-Is-Actually-A-Prude joke in there but people don't get past that one line to appreciate it, it actually subverts comic relief.