Ashley made a guest appearance in last night’s episode of How I Met Your Mother as Barney’s half-sister, Carly Whittaker.

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Television > How I Met Your Mother (2013) > 8.14 – Ring Up! (Screencaptures)

As if Spring Breakers trailer isn’t enough, here’s another teaser video for Ashley’s guest appearance on next week’s episode of “How I Met Your Mother”, where she plays Ted’s girlfriend. Watch the clip below.

How I Met Your Mother 8×14 “Ring Up!” guest starring Ashley Benson (from “Pretty Little Liars”) – Barney begs Ted to continue seeing his much younger, much wilder girlfriend, even though Ted has nothing in common with her. Meanwhile, Robin must adjust to the power of the bling, on HOW I MET YOUR MOTHER, Monday, Jan. 21st on CBS.

Ashley Benson is set to appear in a January episode, playing a character somehow close to Barney (Neil Patrick Harris).

File this under late night Twitter developments: Pretty Little Liars’ Ashley Benson is heading to How I Met Your Mother.

CBS confirms Wednesday’s cryptic announcement — “#PrettyLittleLiars’ @AshBenzo is going to guest star as Barney’s???? on Jan. 21! Suit Up!” — that the ABC Family star recently taped a guest spot for the comedy’s eighth season.

And while the news of a Barney (Neil Patrick Harris) storyline hints that Benson might play one of the lady-killer’s many (would-be) conquests, the character isn’t technically on the market. Barney, again pushing Robin (Cobie Smulders) to the side, has been dating his ex’s nemesis, Patrice (Ellen D. Williams).

Fans won’t have to wait long to find out what exactly Benson is doing on the show. After Monday’s one-hour Christmas outing (with guest Seth Green), the episode in question will be the second of the new year. That’s just two weeks after Pretty Little Liars returns.

Benson is repped by WME.

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