Recently, we have used the MARTINI coarse grained model to elucidate the process of (protein mediated) lipid sorting and the role of relevant fusion proteins, in particular neuronal SNARE molecules and the fusion peptide of influenza hemagglutinin. In my presentation I will first discuss the unsual (non‐helfrich) behavior of liquid ordered domains that is observed when phase segregation occurs above a critical membrane tension. Subsequently, I hope to illustrate that the fusion peptide's of influenza is a typical example of afusion peptide that does not mediate membrane fusion according to the classical example.