And while Lindsay's attendance was enough to send fans surrounding store into frenzy, something in particular caught our attention. The large diamond ring she was sporting, on that finger!
Having just recently admitting that she'd like to settle down with someone soon, Lindsay matched her bling jewellery with a bridal-esque white lace gown designed by Alice Temperley. Dropping any hints with that fashion choice, Lynds?
The Mean Girls actress also took the opportunity to blow out a candle in celebration of her 29th birthday, which she celebrated on 2nd July.
Lindsay, who has just recently moved to London, attended the tasty event along with a handful of celebrity guests including Jameela Jamil, Proudlock and Rosie Fortescue.
The Magnum Pleasure pop up store, which is open for nine weeks, allows visitors to choose from a selection of toppings and sauces to customise their ice cream to make their perfect, personalised choice.
The Magnum Pleasure Store will be open until 30th August 2015 daily #MagnumLDN