Should I tell vegetarian FIL I accidentally gave him meat?

[IndiaKnightGarden]

I just realised my vegetable stock cubes aren't actualky suitable for vegetarians .

I made a risotto with them last week and FIL had some. Should I tell him or keep quiet?

What's wrong with a magnum?

From Unilever:

The products on this list are not suitable for a Vegetarian diet due to the presence of Whey powder which may be sourced from non-vegetarian sources.

Mini Magnum Almond
Mini Magnum Dark (Ecuador)
Mini Magnum Double
Mini Magnum Strawberry Chocolate
Magnum Almond
Magnum Classic
Magnum Dark Ecuador
Magnum Double Caramel
Magnum Java Milk Chocolate
Magnum Temptation Caramel
Magnum Temptation Chocolate
Magnum White
www.answers.com/Q/Are_Magnum_ice_creams_vegetarian

Whey and whey powder are usually by-products of making cheese. Vegetarian whey is a by-product of making veggie cheese. Unfortunately, because it is possible to buy non-vegetarian cheese it is also possible to find whey that is not suitable for vegetarians. Look out for the VegSocApproved symbol to ensure that any products that include whey are suitable for veggies.
www.youngveggie.org/goingveggie/foodstoavoid