The 26-year-old rapper - whose relationship with the 'Break Free' hitmaker was first confirmed in October last year - reportedly turned off his mobile phone whilst they were on holiday so he could give her all his attention.
A source shared: ''When they were up in Tahoe, he basically cut off all communication with the outside world and gave her his complete and undivided attention.
''He turned off his cell phone for the majority of the day.''
Big Sean is believed to be ''incredibly romantic'' towards the 21-year-old singer and is expected to take her on similar trips in the future because it brings them ''closer''.
The source continued: ''He loves this girl big time and all he wants to continue doing is spending time with her and being lovebirds and incredibly romantic.
''He's got more trips like that in store because he knows she loves that kind of stuff and it brings them both much closer to one another.''
The rapper has reportedly been receiving a lot of messages from his exes and female friends, which led Ariana to worry that he was cheating.
However, the increased number of phone calls and text messages from his former flames are believed to be them expressing their condolences, after the rapper recently lost his grandmother.
The source explained to HollywoodLife.com: ''Ariana thought Big Sean was seeing other females because after his grandmother died, a lot of his exes and female friends called him and were telling him that if he needed anything, they were there for him.
''His phone was blowing up with phone calls and texts and he was with Ariana some of the time. She saw girl after girl blowing him up and like most women, her mind automatically assumed he was cheating, but she shouldn't have thought that.''
After nearly thirty years since his first solo record Mark Lanegan has just released one of his very best and there's not many artists who can claim...