Lauren Conrad knows what it feels like to lose a best friend to a guy -- just ask Heidi Montag.
On her official website Thursday, the 26-year-old fashion designer -- currently dating USC law student William Tell, 32 -- responded to a fan who's in a similar conundrum, with Conrad admitting she's "been on both sides" of the spectrum.
"It can be really hard to be the number one priority in someone's life and then suddenly feel like you have been replaced," Conrad wrote. "I think the most important thing to remember is that when you are young, guys come and go, but real friends are forever. Sometimes we have to let our friends enjoy the beginning of a relationship knowing that we won't get to have as much time with them."
Conrad added: "It took me a while to learn this, but it's something that will be returned when you meet a great guy and want to be swept away for a while. My advice would be to do your best to be happy for her and just give her a little time. Then, if nothing changes just be honest about the way you are feeling."
The former MTV reality star -- whose exes include Kyle Howard, Brody Jenner and Stephen Colletti -- has been dating Tell "for a few months," a source recently told Us Weekly. The pair -- who both hail from Orange County -- first met in February. "She hopes he's The One!" a Conrad pal said of Tell, an ex-guitarist for the alternative band Something Corporate.