Solange, 28, has been dating 51-year-old Alan for five years and the pair are now thought to be engaged.
The singer shared a cute snap of herself cuddling up to her beau on Instagram as they celebrated her 28th birthday together on Tuesday.
"Today couldn't have been more perfect," she wrote on the photo sharing site. "I couldn't have smiled harder. Thank you for all of your lovely and wonderful wishes. They warmed my heart and I simply feel grateful for all of the love."
If the wedding rumours turn out to be true this will be the singer's second engagement as she was previously married to Daniel Smith, her high school sweetheart and the father of her son Daniel Julez, from 2004 to 2007.
The pair got hitched in the Bahamas when Solange was just 17-year-old - but despite their split the singer has nothing but kind words on her ex.
"We co-parent really well," she said of her current relationship with Daniel in an interview with Harpers Bazaar. "I'm able to say, 'I need to finish this album, can you step up and take care of the boy?'"
Talking more about her love life she added: "Everyone talks about how, in your 30s, all of these growing pains transition into wisdom and you feel more self-assured and confident, but I think I had a bit of a jump-start on that at 27.
"For the first time in my life, I'm basing every decision around the idea of whether I want to do it or if I think it will be inspiring. And that's paid off for me."
LOVE SOLANGE? See more form Bey's little sister in the gallery below.
MORE! There's more from Solange's interview with Harpers here...