I hate it when my favorite TV shows make me question my loyalty to them. I would never give up on “How I Met Your Mother,” but the news I saw this week has me shaking my head.

Britney Spears will guest star on the May 12 episode, the second time she has appeared on HIMYM this season.

I know she helped give the show an million viewers above its average when she appeared earlier this month, but do you need to sell out again? Neil Patrick Harris spoke out against the worries of stunt casting, then backtracked, which makes me worry that things like this will happen more often.

“Scrubs” is one of my favorite shows, and they have had to endure stunt casting a lot. They have made the most of it a lot of times, but really have delved into some unnecessary story lines just to please the folks at NBC who thought that the guy who played Jack on Will and Grace needed a role that might help him not be typecast as a gay character.

This isn’t the first time HIMYM has put a female into the mix, but this is the most high-profile and the one with the most potential to sidetrack things. Hopefully the storyline with Britney will advance the plot and not just bump up the viewers because of endless promos.

Personally, I’ll be more psyched if Sarah Chalke returns as Ted’s girlfriend (and the boss of Britney’s character).