The model and businesswoman announced her engagement to Leandro Penna yesterday (April 28) following their reunion earlier in the year.
Reid, who was married to Price for 11 months before they separated, reportedly told a friend that the engagement was "a bit of a kick in the teeth", and wished the Argentinian male model luck, saying: "You'll need it."
"Alex thinks it's a good thing Katie and Leandro talk different languages and don't understand each other because he doubts Leandro would stay long," a source said to the Sunday Mirror.
"He loved Katie and was devastated when they split; he did everything he could to make it work and Kate was very cruel during the split."
Price cited Reid's "unreasonable behaviour" as the reason for their divorce. She was previously married to Peter Andre, but they divorced in 2009.
Reid recently apologised to fiancée and fellow Celebrity Big Brother winner Chantelle Houghton after messaging Amy Willerton, the 19-year-old who won Signed By Katie Price.